Modern X-ray imaging technology, used in everything from medical diagnostics to national defence, uses scintillator materials to convert high-energy X-ray photons into visible light. Such scintillator materials typically use large and costly inorganic crystals with low light emission conversion efficiency, which require a high dose of X-rays for effective imaging.

In contrast, X-ray detectors made by incorporating the perovskite nanocrystals into flat-panel X-ray imagers are highly sensitive and can detect doses of X-ray photons approximately 400 times lower than the typical radiation dose used in medical diagnostics today. Using nanocrystals as an alternative scintillator material could also lower costs as they can be produced through less expensive processes at relatively low temperatures.

In addition, the colour of the light emission can be adjusted in response to the X-rays absorbed by the nanocrystals and the resulting images directly recorded using low-cost, widely available digital cameras, or even mobile phone cameras. This is not feasible using conventional bulky scintillators, explained Dr Chen Qiushui, Research Fellow and first author of the study.

All these translate into potentially lower medical expenses and radiation risk to patients, said Professor Liu Xiaogang who led the research team. “Our technology uses a much lower radiation dose to deliver higher resolution images, and it can also be used for rapid, real-time X-ray imaging. It shows great promise in revolutionising imaging technology for the medical and electronics industries,” he added.

Our technology uses a much lower radiation dose to deliver higher resolution images, and it can also be used for rapid, real-time X-ray imaging. It shows great promise in revolutionising imaging technology for the medical and electronics industries.

— Prof Liu Xiaogang, NUS Chemistry

The breakthrough, the result of a collaborative effort with researchers from Australia, China, Hong Kong, Italy, Saudi Arabia, Singapore and the US, was published in the online edition of Nature in August. The team has filed a patent for the novel technology and is looking to work with industry partners for commercialisation opportunities.